当做“while" 用的时候，”一边“和”一面“两个词的用法一样，可以相互代替。比如：他一边吃饭一边看电视。也可以说：他一面吃饭一面看电视。 这个有地域区别，有的地方人用一边多点，有的地方人更喜欢用一面。通常来说用一边的更多。

It's a great question. If you want to differentiate them, you should understand the words at first——words carry meaning. The original meaning of 边 is a side of a geometrical figure: consider a triangle ABC. AB, BC, or CA are 边. As you can see the AB, BC, CA are the borders of the triangle, there is a meaning representing edges, banks, or remote regions. And 面 carries the meaning of "face". Your face is an approximate 2D figure, though strictly it is not. Consider a pyramid ABCDE with summit A on top, we will call ABC, ACD, ADE as 面. However, as you know, a line cuts 2 sides in 2D space, so does 面 separates 2 space in 3D one. We can say 一边... 一边... to express things happen simultaneously. He sang while he worked. 他一边(面)唱歌一边(面)工作

一边 = one side, aside (一边说话一边工作, 放在一边), border, edge (疆边, 傍边) 一面 = one sided(一面之辞), surface, plane (湖面), to face (面聖)

as Mandarin, we won't use 一面 to mean "while", 一边 could mean that. but in Cantonese we could use both. as measure word, 面 means surface; 边 mean side and line.

“一面”还可以用作量词，如：一面红旗。一边也可以用作量词，如：三角形有三条边，其中一边最长。